Apparatus for the manufacture of roofing tiles and the like



Sept. 1, 1953 .s. w.'A. AGAR 2,

APPARATUS FOR THE MANUFACTURE OF ROOFING TILES AND THE LIKE Filed June 24, 1947 INVENTOR Y GEORGE w. A. AGAR ATTK Patented Sept. 1, 1953 APPARATUS FOR THE MANUFACTURE OF ROOFING TILES AND THE LIKE George William Albert Agar, Wellington, New Zealand, assignor to Atlas Products (N. Z.) Limited, Wellington, New Zealand Application June 24, 1947, Serial No. 756,776 In Australia July 3, 1946 6 Claims.

This invention relates to the manufacture of roofing tiles, building blocks, slabs and the like (hereinafter referred to for convenience as tiles) from cementitious and other such plastic materials.

More especially, the invention relates to an apparatus for the purposes indicated as disclosed in the specification of our prior Commonwealth Patent No. 105,651, dated the 27th of May 1937, granted in the name of Oliver Joseph Oakley.

We have operated under the said patent for a number of years and have found that the patented method and apparatus is capably of highly efficient results. Our practical experience has, however, shown that, in certain respects, the method and apparatus can be improved in order to yield even more satisfactory results in actual practice.

According to one important feature of the patented invention, a charge of plastic material is carried upon travelling mould plates beneath a pressing roller or the like which is alternatively moved in combined rearward and upward direction relative to the line of travel of the mould plates, from its position of maximum compression and returned in a combined forward and downward direction to such compression position. At certain stages of its reciprocatory movement, the roller is rotated about its axis and at other times it is held against rotation, the general action of the roller being described with reference to Figures 9 to 12 of the drawings annexed to the said specification.

The operation of the invention under practical working conditions has demonstrated that, in order to obtain consistent uniformity to mould tiles with plastic materials of varying degrees of fineness or coarseness or of varying moisture content, which conditions are inevitable in commercial manufacture, it is highly desirable to provide for precise control of the thicknesses of the layer or web of plastic materia1 being fed towards the compression roller. Similarly, to permit satisfactory continuous working of the method and machine, such control must be operable while the machine is in action.

One of the objects of the present invention, therefore, is to providefor such control in the feed of material to the compression roller.

As a subsidiary or ancillary object, we also aim to subject the material as it is being fed towards the compression roller to an agitation or aeration treatment which ensures that the layer of material being fed towards the compression roller will be of uniform density throughiii) 2 out, neither too loosely, nor too densely, packed.

Our experience has also demonstrated that the degree of rotation imparted to the compression roller after it has completed its compressing stroke, has an important bearing on the satisfactory moulding of the tiles and we contemplate an improved means for controlling the rotation of the roller so that it may operate to the best effect.

The foregoing and various other objects, features and advantages of the invention will be more fully described in, or become apparent from, the following description relatin to an embodiment of the invention which is illustrated in the accompanying drawings- Figure l is a side elevation showing, in general outline, some of the parts of a machine according to Patent No. 105,651 and also showing a feed control feature of the present invention.

Figure 2 is a side elevation on a larger scale of the feed control feature, from the opposite side of the machine to that depicted in Figure 1.

Figure 3 is a front View of the machine.

Fi ure 4 is a side view of mechanism for rotating the compression roller under controlled conditions,

Figure 5 is an end view of Figure 4.

Figure 6 is a cross-sectional view taken on line 56 of Figure 3.

Before describing the present improvements it may be mentioned that, as in our prior patent, the plastic material is delivered onto mould plates conveyed by endless chains A (Figure 1) passing around sprockets S supported by frame F, beneath the compression roller 3, mounted at the lower ends of two levers L which are pivoted at P slightly above the roller axle RA. The levers L are influenced by a cam member C and other mechanism as disclosed in the aforesaid patent specification.

According to one feature of the invention, we provide a feed control device in the form of a plate or blade 2 which extends transversely in front of the compression roller 3, i. e., at the feeding side thereof, and which is mounted and operated so as to enable precisely the desired rate of forward feed of the material to be obtained, depending upon the fineness, coarseness, moisture content or other variable factors of the plastic material. This plate or blade is preferably given a somewhat rectilinear motion, in appropriate synchronism with the movement of the compression roller 3, the lower horizontal component of the movement being away from the compression roller and the upper horizontal component being in the opposite direction. For this purpose, the plate or blade may be actuated by eccentrics, cams, connecting rods, a lever and link system or the like which is driven from an overhead shaft, or in such manner as may be desired.

A preferred means of effecting such a movement is illustrated with particular reference to Figures 2 and 3, wherein the feed control plate 2 is suspended from bracket 4 which may be connected by integral yoke formation 4a to and driven by eccentric pins 6 formed at the extremities of a rotatable shaft 7 borne upon an adjustable sliding head 8. The shaft may be driven by chain or like drive 9 from the main cam shaft I l.

The sliding head 8 is mounted upon a support plate l2 secured to the machine frame, upward and downward adjustment of the sliding head being effected by means of screw and nut gear l3 actuated by hand-wheel l3a.

Intermediate of its length the bracket 4 may be connected by a link Ill, which may be adjustable in length, to a pivot IE on a suitable fixed portion of the machine frame work.

However, other suitable operating means may be employed, the operating mechanism being mounted upon a suitable stationary part so that it can be adjusted in a vertical direction as by means of a screw and nut gear operated by a hand-wheel or the like.

With such an arrangement, it becomes a relatively simple matter for the operator to adjust the mechanism, while the machine is in operation, to ensure a desirable rate of feed of the plastic material, in the form of a layer or web, towards the compression roller.

In operating under the aforesaid patented invention, it has been found that, under certain conditions, there was a tendency for the material being fed towards the compression roller to be rolled or packed into a relatively dense mass which could not be adequately or properly compressed by the roller into the desired profile and to uniform density. To overcome this disability, we attach a transversely extending horizontal rod to the aforesaid plate or blade, as shown in Figures 2, 3 and 6, so that the rod extends parallel with the plate but several inches in advance thereof, with the result that the oncoming material from the feed hopper is maintained is a state of agitation whereby it is aerated and prevented from packing into a solid mass but kept in a desirable condition that enables it to be fed forwardly by the plate or blade with the utmost consistency, and in a condition which is neither too dense nor too loose.

A further feature of the invention relates to the means and control of rotation of the compression roller after it has completed its compression stroke. According to the illustrated embodiment in patent specification No. 105,651, a pawl and ratchet device is employed but it has been found in practice that such a device does not permit of variation within sufficiently close limits.

According to the present invention, this feature of the prior patent has been improved by the use of a pair of uni-directional self-locking brake hands 22, 25 operating upon drums 24, 26, mounted on the shaft RA carrying the compression roller.

One of the brake bands may be connected to an arm or arms 27 which is under the influence of a crank or connecting rod 28 of adjustable stroke (this may be simply and conveniently effected by providing connection to a crank pin radially adjustable upon an eccentric head), in a somewhat similar manner to the way in which the pawl actuates the ratchet in the prior specification, while the other brake band may be connected to an arm 29, which though capable of slight horizontal movement with the compression roller shaft, is prevented from rotating around the latter.

Having now described my invention, what I claim as new and desire to secure by Letters Patent is:

1. Apparatus for making articles from cementitious like plastic materials, comprising means for conveying a layer of the material in plastic state past a pressure member, a scraper positioned transversely of the path of the layer and at the feed side of said pressure member, drive mechanism for moving said scraper through a path including a component of movement away from the pressure member and substantially at the relative level of the pressure member to remove excess material from the layer, and rod-like agitating means carried by said scraper spaced from the side of said scraper opposite said pressure member to loosen masses of the material in said layer as the scraper is moved over the layer.

2. Apparatus as defined in claim 1 wherein said agitatingmeans comprises a U-shaped rod extending from said scraper and having its intermediate bridge portion spaced a considerable distance from said scraper.

3. Apparatus for making articles from cementitious like plastic materials, a frame, a pressure roller journalled on said frame, means for driving said pressure roller, means for conveying a layer of the material in plastic state past said pressure roller, a scraper positioned transversely of the path of the layer and at the feed side of said pressure roller, and drive mechanism for moving said scraper through a substantially rectilinear path including two components of movement which are substantially parallel to the layer, with the component nearest the layer being away from the pressure roller and substantially at the relative level of the pressure roller to remove excess material, said drive mechanism including a vertically arranged bracket from which the scraper depends, a crank shaft journalled on said frame, means for driving said crank shaft in synchronism with said roller driving means, bearings at the upper portion of said bracket and journalled on the eccentrics of said crank shaft, and an adjustable link extending between a midportion of said bracket and said frame.

4. Apparatus as defined in claim 3 wherein said bracket is slidably mounted for movement in a substantially vertical plane, and a screw adjustment operatively connected with said bracket for varying its relative height.

5. Apparatus for making articles from cementitious like plastic materals, comprising means for conveying a layer of the material in plastic state. a pressure roller mounted above said conveyor for reciprocatory movement at a substantially uniform level longitudinally of said conveyor, a movable support above said layer, a scraper carried by said support transversely of the path of he layer and at the feed side of said pressure roller, a driven cam for reciprocating said pressure roller, gearing driven with said cam for moving said support to move said scraper through an oscil atory path away from the pressure roller in synchronism with reciprocation of said roller and substantially at the relative level of the pressure roller to remove excess material. and means for adjustably securing said scraper to said support to vary the height of said scraper relative to the layer.

6. Apparatus as defined in claim 1 wherein said scraper is carried by a support which is operatively connected with said drive mechanism, said scraper being adjustably depended from said support for variation of its elevation relative to said conveying means, and an adjustment devic carried by said support and operatively connected with said scraper, said adjustment device being operative during operation of said drive mechanism for selectively adjusting said scraper relative to said support to vary the thickness of the layer and control the density of the material under said pressure member.

GEORGE WILLIAM ALBERT AGAR.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 979,547 Norton Dec. 27, 1910 1,619,489 Schwarz et a1 Mar. 1, 1927 1,619,490 Schwarz Mar. 1, 1927 1,768,141 Pfeffer et a1 June '24, 1930 FOREIGN PATENTS Number Country Date 105,651 Australia Oct. 27, 1938 

